CVE-2026-58654

MEDIUM
Published Jul 8, 2026 Modified Jul 8, 2026 CWE-434

Description

The Grav API plugin (getgrav/grav-plugin-api) 1.0.0 contains an unrestricted file upload vulnerability in the avatar upload endpoint (/api/v1/users/user/avatar). The endpoint validates only the client-declared MIME type (getClientMediaType) beginning with 'image/' and does not inspect the actual file content or restrict the resulting extension, allowing an authenticated user to store arbitrary content — including PHP code, SVG with embedded JavaScript, and polyglot payloads — under user/accounts/avatars/ with predictable filenames. Direct HTTP access to the stored files is blocked by .htaccess (returns 403), but the files persist on disk and could lead to remote code execution or stored XSS in the presence of a path traversal flaw or server misconfiguration. Fixed in 1.0.1.

Is your site exposed to CVE-2026-58654?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

4.3
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

EPSS — Exploit Prediction

0.0026
Probability of exploitation
0.18%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-434 Unrestricted Upload

References

Frequently Asked Questions

What is CVE-2026-58654? +
The Grav API plugin (getgrav/grav-plugin-api) 1.0.0 contains an unrestricted file upload vulnerability in the avatar upload endpoint (/api/v1/users/user/avatar). The endpoint validates only the client-declared MIME type (getClientMediaType) beginning with 'image/' and does not inspect the actual file content or restrict the resulting extension, allowing an authenticated user to store arbitrary content — including PHP code, SVG with embedded JavaScript, and polyglot payloads — under user/accounts/avatars/ with predictable filenames. Direct HTTP access to the stored files is blocked by .htaccess (returns 403), but the files persist on disk and could lead to remote code execution or stored XSS in the presence of a path traversal flaw or server misconfiguration. Fixed in 1.0.1. It has a CVSS v3.1 base score of 4.3 (MEDIUM).
How severe is CVE-2026-58654? +
CVE-2026-58654 has a CVSS v3.1 score of 4.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0026, placing it in the 0th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-58654? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-3219

pip handles concatenated tar and ZIP files as ZIP files regardless of filename or whether a file is both a …
CVE-2024-43662

The <redacted>.exe or <redacted>.exe CGI binary can be used to upload arbitrary files to /tmp/upload/ or /tmp/ respectively as any …
CVE-2026-41517

Emlog is an open source website building system. Prior to version 2.6.11, insecure plugin upload functionality allows attackers to upload …
CVE-2026-5482

Responsive FileManager's allows an unauthenticated attacker to upload files of any type and extension without restriction using dialog.php endpoint, leading …
CVE-2026-34027

The Wertheim SafeController Software, AssemblyVersion 6.15.8328.28014, contains insufficient server-side file type validation in the /safe/contract/uploadcustomdocuments endpoint. The application validates uploaded …
CVE-2019-25714

Seeyon OA A8 contains an unauthenticated arbitrary file write vulnerability in the /seeyon/htmlofficeservlet endpoint that allows remote attackers to write …

Don't wait for an exploit

Scan your website for vulnerabilities like CVE-2026-58654 — free, no signup required.